1. Field of the Invention
The present invention relates to a cable ends termination assembly, the method of assembling the termination assembly and the apparatus for assembling the structure of the cable ends to produce the termination assembly.
2. Technical Background of the Invention
Generally, electrical signal transmission is carried out through wires termed signal wires which carry signal data and ground wires which connect to the ground. However, it should be noted that in this invention the structural configuration of both wires is the same, and therefore the wires are interchangeable to carry either the signal current or the grounding current.
Conventionally, when it is necessary to provide a plurality of signal wires (first wire) for electrical devices, three types of wire configuration were used: round cables having many signal wires; a plurality of twisted pair signal wires and an adjacent ground wire (second wire); and a flat cable configuration having a plurality of signal wires laid side by side encased in a sheath.
In the round cable configuration, a plurality of insulated signal wires and an adjacent ground wire are bundled together with an insulated outer sheath.
In the pair cable configuration, a plurality of insulated signal wires and adjacent exposed ground wires are bundled with an insulating outer sheath, and the terminal ends of the signal wires and the ground wire extending out of the insulated section are arranged flat and are connected to the contacting elements of an electrical device. In such pair cables, the signal and ground wires are positioned by inserting one wire each in the wire guiding grooves formed on the top surface of a plate receptor of the plug-in casing. The terminal ends of the wires are attached to the contacting elements (for contacting the device) by such means as soldering and spot welding, and the assembly are integrally molded by injection molding. This is followed by disposing a printed circuit board between the contacting elements and the pair cable, in which the printed circuit board serves as wiring means to transmit the signals through the pair cable.
The round cable configuration mentioned above has the tendency to be bulky because of the number of insulated signal wires which are bundled together. Therefore, the joining section joining the round cable to the contacting elements tended to be bulky, and it was difficult to join the round cable to modern miniaturized electrical devices.
For the pair cable on the other hand, because of the process of injection molding, the terminal ends of the signal and ground wires are pressed by the resin at elevated temperatures, and there was the danger of debonding of the wires from the contacting elements causing severing of the electrical connections. Further, because the signal wires and the ground wires are arranged within a common plane, there was a danger of the signal wires coming into contact with the ground wires. Further, when a printed circuit board is utilized for the purpose of distributing the signals, the board must be custom fabricated for each application, leading to high expenses and manufacturing effort. Further, there is a danger of increasing contact resistance because of the duplicate bonding connections involved, the contacting elements bonded to the printed circuit board which is bonded to the ends of the pair cable.
In using the flat configuration, because the signal wires are laid out in a flat configuration, it was difficult to route the signal wires to specific locations required. Further, in distributing the signal wires to several locations, the wires are stripped from the insulation and routed to the specified location, thus leading to complex tangling of the signal wires.
Furthermore, when the distance between the flat cable ends and the wiring locations in a connector are different, different lengths are required for each of the signal wires. There are many cases of wastage in the past, caused by insufficient lengths of the signal wires. Such signal wires are not only wasted, but the wire ends must be treated in some way, resulting in uneconomic manufacturing process.